The invention concerns a process and apparatus for the preparation of book covers.
A process and apparatus for carrying out the process are known from a Brochure No. D 017.0869, which describes a book cover machine designated as BDM 20 of the Maschinenfabrik Michael Horauf Co., West Germany. A mechanism designed therein as a "second contact pressure unit" serves to re-press book covers, the covering sheets of which are glued to cardboard panels and folded around their edges. For this purpose, a so-called re-pressing belt is provided, which passes the book covers through the roll gap of a pair of contact pressure rolls. Re-pressing is carried out continuously per each cover in the sense that re-pressing forces are applied to the edges of the panels in an uninterrupted manner, i.e., once the forces are begun at leading ends of the edges to be pressed, the forces are not relieved until the trailing edges are reached.
With many covering materials, in particular in the case of embossed book coverings, occasionally small folds form at the trailing edge of the cover, which lead to the formation of small voids between the book covering and the corresponding cardboard cover. Such voids are undesirable relative to the appearance and the durability of book covers.
It is an object of the invention to eliminate this disadvantage and to provide a process and an apparatus for the production of book covers, whereby the book coverings will adhere fully to the cardboard covers.